quill gordon , key to hatch activity is water temp , 50 degrees for a few days in sucession will trigger the hatch , 4 days approx. the spinners will show up at the warmest part of the day (12-2) over the riffles , they will continue to hatch despite the weather once they start hatching , water must be pure and no pollutants , high silt content , factory discharge 9warm water ) etc. if you have good hatches of quill gordons u have awesome water quality . nymphs do emerger subsurface as someone already mentioned , they migrate to the downstream side of rocks late to mid morning , making a nymph pattern in the am pre hatch killer , during a hatch a emerger pattern such as a soft hackle hares ear is killer , nymphs sizes 10,12 standard , surface size 10,12,14 peak emergence is usually between 12:30 - 2:30 but cold drizzly days 2-4 when it is warmest , trout sip the spinners pretty inconspicously so you gota really watch for them , not gonna splash water like a caddis hatch .. if spinners and duns are both on the water , trout usually ignore the spinners (in slower stretches of water ) but in faster water the spinners out # the duns and a spinner seems to work better . i am by no means a expert but i think this may help some and most probably already know this stuff , sorry about the long post fellas just trying to help and i don't think i even spot burned in this one ...lmao 1 other thing if the quills are not hatching put on a san juan worm ....hehehheeee